Signalling device



y 9, 1967 w. R. AIKEN 3,319,246

SIGNALLING DEVICE Fi led June 1, 1964 2 Sheets-Sheet 1 FIGZA I WILLIAM ROSS AIKEN United States Patent Ofifice 3,319,246 Patented May 9, 1967 3,319,246 SIGNALLING DEVICE William R. Aiken, Los Altos Hills, Calif., assignor to Electronix Ten, Inc., San Francisco, Calif., a corporation of California Filed June 1, 1964, Ser. No. 371,638 5 Claims. (Cl. 340-673) The present invention relates to signalling devices of the type employing relatively movable components to display, expose or conceal an identifying mark, such as a brightly painted surface, a number, a warning inscription, and the like. More particularly, the present invention relates to adjustable signalling devices of the type referred to, wherein the relative movement of the sign-displaying and concealing components is accomplished by the repelling and attracting elfect of electrostatic charges. Signa-lling devices of the type to which the present invention relates are described in my US. Patent No. 2,912,674 issued Nov. 10, 1959, for an Adjustable Sign.

In devices of this type, a thin sheet or vane is hingedly supported from a base for swinging movement from a position substantially parallel and adjacent to said base to a position substantially at right angles to said first position, and this movement is effected by the repelling and/or attracting forces of electrostatic charges that are applied to said vane and said base and/ or electrodes located adjacent to and/ or above said vane.

It is an object of this invention to provide an improved signalling device of the type referred to, wherein the vane is dependably raised from an initial substantially horizontal position to a practically vertical position by the application of electrostatic charges.

Still another object of the invention is to provide a signalling device of the type referred to, whose vane may be dependably raised into practically vertical position by the'application of electrostatic charges to a plurality of field-producing electrodes, and will remain in vertical position even though the movement-effecting electrostatic charges may be withdrawn from all but one of said electrodes.

Yet another object of the invention is to provide a signalling device of the type referred to, with means for returning the raised vane from a vertical position dependably to its initial substantially horizontal position.

These and other objects of the present invention will be apparent from the following description of the accompanying drawings which illustrate a preferred embodiment thereof and wherein FIGURE 1 is a fragmentary perspective of a signalling device embodying the invention; and

FIGURES 2A, 2B, 2C and 2D are somewhat schematic vertical cross sections through the signalling device illustrating different operational positions thereof.

The signalling device of the invention comprises a suitable base 10, and supported upon said base is a thin layer 12 of electrically conductive material, such as a sheet of metal foil that may be glued to the base, a coat of conductive paint or a plate of metal. Hingedly supported near the front edge of the base is a thin sheet-shaped vane 14 which may likewise be of metal foil, but may also be of a plastic material such as the material known as cellophane. The upper or outer surface of the vane v14 may be provided with an identifying mark such as a conspicuous coat of paint indicated at 15. In the embodiment of the invention illustrated in FIGURE 1, said vane is hingedly supported from the base by thin strips of a flexible material which are indicated at 16, and the base is provided with a number of spacer beads indicated at 17. These beads prevent contact of the vane with the base electrode 12 which might hinder initial upward movement of said vane during operation of the device.

The spacers 17, are preferably of such height that the vane lies, in its position of rest, in a plane that diverges somewhat from the base 10, as best shown in FIG- URE 2A.

The signalling device of the invention has also a pair of vertically disposed side walls 18a and 18b (FIGURE 1) which may be of the same material as the base 10 and may in fact form an integral structure with said base. Arranged along the inner surfaces of said side walls are sheet-shaped electrodes 20a and 20b, respectively, which may again be coats of conductive paint or sheets of metal foil that are glued to the side walls. The signalling device of the invention may also be provided with a roof or ceiling 24 which may be made from the same material as, and be integral with, the hereinbefore described side walls 18 of the device. In accordance with the invention two separate electrodes 26 and 28 of different size are arranged in juxtaposition upon the inner surface of the roof or ceiling 24. The electrode 28 is the larger one and may be formed by a coat of paint or sheet of metal foil that is glued to and covers the major portion of the ceiling except for the frontal area thereof. Said frontal area is occupied by the smaller electrode 26 which may be formed by a strip of metal foil or a coat of conductive paint or even a rod of conductive material, that is entirely separated from the rear electrode 28. The front of the signalling device may be left open, but if it is desirable to protect its interior from atmospheric influences,

a window may be provided which should be spaced an appropriate distance from the front edges of the adjacent electrodes comprised in the device, to minimize electrostatic interference of the window with the intended performance of these electrodes. The device of the invention does not rquire a rear wall; the exemplary embodiment of the invention illustrated in the accompanying drawings, however, is provided with a rear wall 22 which may form an integral structure with the base, the side wall and the top wall of the device and which is appropriately spaced from the rear edges of the adjacent electrodes to minimize electrostatic interference of the rear wall with the intended performance of the device.

' In the preferred embodiment of the invention illustrated in the accompanying drawings, the bottom electrode 12 and the vane 14 are jointly connected to a source of positive potential as indicated at 29. Both the side electrodes 20a and 20]) may jointly be connected to a common source of negative potential by a switch 30 which is initially in an open position as shown in FIGURE 2A. Similarly the top electrode 28 may be connected to said source of negative potential by a switch 32 which is initially in an open position. The top electrode 26, however, is initially usually connected to a source of potential that is negative with respect to the potential to which the base electrode and the vane are connected, as indicated by the switch 34 in FIGURE 2A.

When the switches 30 and 32 are operated to set the side electrodes 20a, 20b and the top electrode 28 to a potential that is negative with respect to the potential applied to the base electrode 12 and the vane 14, said vane rises to the steeply tilted position illustrated in FIGURE 2B, which may approach but will not reach a truly vertical plane because as the vane in rising from its almost horizontal position reaches inclinations of more than 45 degrees, the parts of the side electrodes 20a and 20b rearwardly of the rising vane, and eventually also the part of the top electrode 28 rearwardly of the rising vane, exert attractions upon said vane that tend to pull it backwardly. By splitting the top electrode into a frontal and a rear portion in accordance with my invention and by providing for separate switch means for controlling the potentials applied to said top electrode portions, it is possible to elevate the vane to a fully vertical position. It is merely necessary after the vane has reached its highest possible position (FIGURE 2B) to return the switches 30 and 32 to their initial ie. open positions and thus restore the side electrodes and the rear portion of the top electrode to their initial neutral potentials (FIGURE 2C). When the rearwardly attracting forces set up by said side electrodes 20a, 20b and by the top electrode portion 28 are thus abolished, while the front portion 26 of the top electrode retains its attracting potential, said front electrode pulls the vane into a fully vertical position as illustrated in FIGURE 2C; and whatever mark 15 may be provided on its outer surface may now be clearly seen by a person viewing the device.

To return the vane 14 from its vertical position dependably to its initial position upon opening of switch 34 and resultant deenergization of the frontal top electrode 26, said sheet may be provided with a return spring indicated at 38 or a suitable counter weight may be attached to the rear face of the vane as indicated at 40. Said counter weight is preferably located close to the hinges 16 so that it may have a minimum effect upon the upward movement of the vane during the initial stages in its rotation from its horizontal to its vertical position. Alternatively, the side electrodes 20a, 20b and/ or the rearwardly located top electrode 28 may be briefly connected to the source of negative potential by closure of the switches 30 and 32 (FIGURE 2D) to establish an attracting electrostatic field that pulls the vane rearwardly out of its vertical dead center position so that upon reopening of said switches 30 and 32 and the resultant collapse of the electrostatic field set up by the side electrodes and/or the rearwardly located top electrode, the vane 14 drops under its own gravity into its initial position as established by the spacers 17.

By the described electrode arrangement it is now possible to raise the control vane in signalling devices of the type here under consideration, from a horizontal position dependably into truly vertical position and to retain it in this position with a minimum of energy and without retaining attracting potentials upon the electrodes that moved it initially to its vertical position; and it is also possible to return the vane from said vertical position without fail to its initial position if and when desired. The described signalling device operates with equal effectiveness when a negative potential is initially applied to all the electrodes and the vane, and the side and top electrodes are afterwards grounded to swing the sheet into its upright position. The same is true when all the electrodes and the vane are initially grounded and a correspondingly higher positive potential is afterwards applied to the top and the side electrodes.

While I have described by invention with the aid of a particular embodiment thereof, it will be understood that the invention is not limited to the specific constructional details or circuit connections shown and describe-d by Way of example, which may be departed from without departing from the scope and spirit of the invention.

I claim:

1. A signalling device comprising a vane hingedly supported for swinging movement from a substantially ere,

horizontal position to a substantially vertical position, a first electrode arranged adjacent the free end of said vane in said substantially vertical position thereof, a second electrode substantially in juxtaposition with but separated from said first electrode, means operable to apply to said first electrode a vane-attracting potential and separate means operable to apply to said second electrode a vane-attracting potential.

2. A signalling device comprising a substantially horizontally disposed base electrode, a vane supported for swinging movement from a position adjacent said base electrode to a substantially vertical position, a first top electrode arranged above said vane in said substantially vertical position thereof, a second top electrode substantially in juxtaposition with but separated from said first top electrode, means operable to apply to said first top electrode a vane-attracting potential, and separate.

means operable to apply to said second top electrode a vane-attracting potential.

3. A signalling device comprising a horizontally disposed base electrode, a vane supported adjacent said base electrode for swinging movement from a position adjacent to said base electrode to a substantially vertical position, electrodes disposed at either side of said vane, a first top electrode arranged above said vane in its vertical position, a second top electrode substantially in juxtaposition with but separated from said first top electrode, means operable to apply a vane-attracting potential to said first top electrode, and means operable to apply a vane-attracting potential to said second top electrode.

4. A signalling device comprising a horizontally disposed sheet-shaped base electrode, a vane supported adjacent an edge of said base electrode for swinging movement from a position adjacent to said base electrode to a substantially vertical position, sheetashaped electrodes disposed at either side of said base electrode and said vane, a first top electrode arranged above said vane in its vertical position, a second top electrode in juxtaposition with but separated from said first top electrode, means operable to apply to said side electrodes a vane-attracting potential, means initially set to apply to said first top electrode a vane-attracting potential and operable to withdraw said vane-attracting potential from said first top electrode, and means operable to apply to said second top electrode a vane-attracting potential.

5. A signalling device according to claim 4 including spacer means arranged to maintain said vane when in the position adjacent said base electrode, in a plane diverging from said base electrode.

References Cited by the Examiner UNITED STATES PATENTS 888,241 5/ 1908 Kuhlmann 20 O87 3,042,823 7/1962 Willard 340166 X 3,089,120 5/1963 Aiken 34044 NEIL C. READ, Primary Examiner.

I. I. LEVIN, Assistant Examiner. 

1. A SIGNALLING DEVICE COMPRISING A VANE HINGEDLY SUPPORTED FOR SWINGING MOVEMENT FROM A SUBSTANTIALLY HORIZONTAL POSITION TO A SUBSTANTIALLY VERTICAL POSITION, A FIRST ELECTRODE ARRANGED ADJACENT THE FREE END OF SAID VANE IN SAID SUBSTANTIALLY VERTICAL POSITION THEREOF, A SECOND ELECTRODE SUBSTANTIALLY IN JUXTAPOSITION WITH BUT SEPARATED FROM SAID FIRST ELECTRODE, MEANS OPERABLE TO APPLY TO SAID FIRST ELECTRODE A VANE-ATTRAWCTING POTENTIAL AND SEPARATE MEANS OPERABLE TO APPLY TO SAID SECOND ELECTRODE A VANE-ATTRACTING POTENTIAL. 